(1) Field of the Invention
The present invention relates to an evaporated fuel treating device.
(2) Description of Related Art
Conventionally, an evaporated fuel treating device (hereinafter this may be called a canister) is used to temporarily adsorb a fuel component in evaporated fuel so as to prevent emission of the evaporated fuel from a fuel tank of a vehicle or the like to the atmosphere.
In recent years, a canister is required to reduce the diffusion amount of evaporated fuel to the atmosphere. As a canister with less diffusion amount of evaporated fuel to the atmosphere, a canister 101 as illustrated in FIG. 19 is known, including a casing 105 provided with a tank port 102, a purge port 103 and an atmospheric port 104. In the casing 105 are formed a first housing chamber 106 and a second housing chamber 107, the first housing chamber 106 communicating with the tank port 102 and the purge port 103, and the second housing chamber 107 communicating with the atmospheric port 104. The first housing chamber 106 and the second housing chamber 107 communicate with each other on the opposite side to the atmospheric port 104, and on the side of the atmospheric port 104 in the second housing chamber 107 is formed a first activated carbon chamber 108 filled with activated carbon. On the opposite side to the atmospheric port 104 side of the first activated carbon chamber 108 in the second housing chamber 107 is formed a space chamber 109 filled with no activated carbon, and on the opposite side to the atmospheric port 104 side of the space chamber 109 in the second housing chamber 107 is formed a second activated carbon chamber 110 filled with activated carbon, and in the first housing chamber 106 is formed a third activated carbon chamber 111 filled with activated carbon (for example, refer to JP-A-2005-195007).
In this canister 101, between the first activated carbon chamber 108 and the second activated carbon chamber 110 is provided the space chamber 109 so as to suppress diffusion of evaporated fuel to the first activated carbon chamber 108, thereby reducing the diffusion amount of evaporated fuel to the atmosphere.
In the aforementioned conventional canister 101, between the space chamber 109 and first activated carbon chamber 108 and between the space chamber 109 and the second activated carbon chamber 110 are provided a plate 113 and 114, and all over the plate 113 and 114 are formed communication holes 115. Therefore, this conventional canister fails to delay diffusion of evaporated fuel to the first activated carbon chamber 108 effectively.